A Guide to Radio Frequency Identification (RFID)

What Are the Types of RFID Technology?

RFID technology is categorized by a radio frequency range.  Each frequency serves specific needs, providing flexibility across various industries.

Low Frequency (LF)

30–300 kHz commonly operates at 125 kHz or 134.2 kHz with short read ranges (~10 cm) but is less susceptible to interference from metals or liquids. Ideal for animal tracking, access control systems, medical procedures and industrial automation.

High Frequency (HF)

Frequency Range: 3–30 MHz operates at 13.56 MHz with a range of up to 1 meter and can add security features and write data to the tag. Ideal for access control systems, library books, MRO and embedding into products such as tool tracking.

Near Field Communication (NFC)

A subset of HF RFID technology and operates at the 13.56 MHz but allows for two-way short-range communication — typically between an NFC tag and a smartphone or tablet — limited to 10cm. Commonly used in contactless payments in Apple Pay, Google Pay, digital wallets and public transit.

Ultra-High Frequency (UHF)

Operates at 860-960 MHz with a range of up to 15 meters (~49 ft) and a higher data transfer rate than other RFID frequencies. However, UHF systems are more sensitive to interference from liquids and metals. UHF is commonly used in supply chain management, asset tracking, inventory control and toll collection systems. EPC Class 1 Gen 2 or RAIN RFID is a widely held standard suitable for global retail, logistics and inventory management applications.

Active RFID Tags, LoRaWAN

Active RFID tags, including Bluetooth Low Energy (BLE) and WiFi-based RFID, operate at different frequencies and offer distinct advantages over passive RFID due to their built-in battery. BLE RFID tags typically operate at 2.4 GHz, providing a balance between energy efficiency and range, making them ideal for real-time location tracking in applications such as asset management, healthcare and smart buildings. LoRaWAN operates at 433 MHz (used in Asia and parts of Europe), 868 MHz (used in Europe) and 915 MHz (used in North America and other regions). LoRaWAN enables long-range (up to a few kilometers) and low-power consumption communication. Main use cases include smart cities, asset tracking, leak detection and similar applications. WiFi-based RFID tags operate at 2.4 GHz or 5 GHz, leveraging existing network infrastructure for seamless integration into enterprise systems. Because active RFID tags are battery-powered, they offer a much greater range (often up to 100 meters or more) and faster data transmission than passive RFID. These capabilities make them well-suited for scenarios requiring continuous tracking, real-time monitoring and enhanced data capture, such as fleet management, high-value asset tracking and automated security systems. However, their reliance on a battery means they require periodic maintenance and replacement, which should be factored into deployment strategies.

What Are RFID Tags and How Do They Work?

RFID technology operates by using radio waves to transfer data between a tag and a reader.

Passive RFID Tags

These are the most common type of RFID tags and do not have a built-in battery. Instead, passive RFID tags are powered by a stationary or mobile RFID reader that emits an electromagnetic field. The tag’s antenna harvests energy from this field to process and release a signal back to the reader. The tag’s antenna captures this energy, which it uses to process and transmit data back to the reader. For passive tags, low-, high- and ultra-high frequencies are standardized (LF, HF, UHF).

Active RFID Tags

Active RFID tags are equipped with an internal battery. This allows them to transmit signals autonomously and achieve a longer range. They are particularly useful for applications such as WiFi or Bluetooth Low Energy (BLE)-based tracking and monitoring in larger or more dynamic environments. Because active tags are always on and do not rely on a reader to energize them, they can be read by an active gateway at distances much further than passive RFID tags.

What Is the RFID Tag Format for Data?

In general, an RFID tag represents data that can be written in usually hexadecimal or ASCII data format. Some chips are more capable than others. For example, they may provide a file system or reserved memory areas for certain standardized pieces of data. Many proprietary formats exist on the market, but there are also some standardized formats that allow interoperability between RFID tags, readers and applications from different vendors. Some public data format examples include:

Can RFID Read Multiple Tags at The Same Time?

Both High Frequency (HF) and Ultra-High Frequency (UHF) RFID systems can scan multiple tags simultaneously, significantly improving efficiency in operations like inventory management. For instance, modern UHF RFID readers can process over 1,000 tags per second, making large-scale scanning tasks much faster and more efficient compared to barcode systems. This scalability and speed make RFID a highly effective tool in a wide range of applications.

Additionally, RFID tags can store more data than traditional 1-D barcodes, offering enhanced flexibility for complex applications. Certain HF RFID tags even allow data to be written and updated dynamically, enabling real-time adjustments and tracking.  Furthermore, RFID tags can integrate with sensors to monitor variables like temperature, humidity and other environmental conditions.

RFID technology also supports advanced security features, such as cryptographic protocols, dynamic security and tamper detection through electronic seals, providing added protection for sensitive or high-value assets.

What Are the Common Challenges with RFID Tags?

While RFID offers significant advantages, it also presents several challenges that must be addressed for optimal performance. Proper system design, careful tag selection and application-specific strategies can help overcome these issues.  Make sure to consult with an HID RFID expert before jumping into your first RFID project.

• Metals: Metals can significantly impact the performance of RFID tags, particularly higher-frequency tags like Ultra-High Frequency (UHF). Tags placed directly on metal surfaces often fail to read. Specialized on-metal RFID tags are available, featuring housings that create a controlled gap or metal foils designed for optimized performance near metal surfaces.
• Moisture: Moisture can reduce the read range of RFID tags, especially at higher frequencies. While Low Frequency (LF) tags are largely unaffected by water, UHF tags experience significant range reduction when wet. Tags placed too closely together can also interfere with each other, especially UHF tags. Minimum spacing guidelines for each tag type must be adhered to in order to maintain readability and prevent collisions.
• Fixation: Proper attachment of RFID tags to surfaces is crucial for reliable performance. Adhesive fixation requires maximum contact between the tag and the surface to ensure durability, especially in environments exposed to mechanical shock or vibration. For tips on effective tag mounting, specialized resources like the Adhesive Tag Fixation guide are invaluable.
• Cost Considerations: Active tags include batteries and durable enclosures, making them more expensive but suitable for long-range and autonomous tracking applications. Whereas UHF passive tags are generally more affordable and maintenance-free but may not be suitable for all applications, particularly those requiring extended read ranges or harsh environmental conditions.
• Data Management: Efficient data collection, storage and security are critical in RFID systems. Passive tags continuously transmit data in the presence of a reader or antenna, so selecting the right software and implementing robust security protocols is essential to ensure data usability and protection.

What Are Typical RFID Tag Form Factors?

RFID tags can come in various form factors depending on use case, fixation and requirements for robustness of the RFID device. Typical form factors include:

• Paper or PET label with adhesive “sticky label” or without adhesive “dry inlay”
• Glass capsule
• Disc (coin shape with hole) that can be embedded or epoxied
• Hard Tag (often with screw holes or steel ring to weld)
• Packaged tags
• Card such as security badge, ISO card, credit card
• Special form factors, e.g., with built-in cable tie, tamper protection, keyfob

What Is the Distance/Range of RFID Tags?

RFID reading distance depends on several factors, including:

• Size of the tag’s antenna
• Tag chip
• Tag’s orientation in the reader field
• Type of reader device and strength of the reader field which can depend on whether using a fixed RFID reader or a handheld mobile reader
• Environmental factors like metal, water or other material around the tag
• LF tags have short read ranges up to 4 in (~10 cm)
• HF tags have medium read ranges up to 3 ft (up to 1m)
• UHF near-field tags typically have a reading distance up to 1 ft (30 cm)
• UHF far-field tags typically have a reading distance of several m/ft but are strongly dependent on the environment
• NFC Tags (HF) are designed for near-field communication with a smartphone or similar device and typically have a reading distance of ~2 in (5 cm)

What Are NFC Tags?

NFC (Near Field Communication) tags are passive, high-frequency (HF) RFID tags that contain an NFC Data Exchange Format (NDEF) compliant data structure as defined by the NFC Forum. NDEF data, like a URL or contact, is understood by any NFC-compliant reader device, such as a mobile phone, without requiring an extra API. See the white paper The Power of Choice: From Standard NFC to Secure Solutions for more detailed information.

NFC Tag Uses

NFC tags are commonly used for various applications, including:

• NFC tags are often used as a convenient replacement for a QR code and simply host a URL that is opened when the tag is tapped with an NFC phone
• NFC tags may also host other information, such as contacts, images, actions or phone numbers
• Public transport tickets may be NFC tags
• Secure NFC tags like the HID Trusted Tag open up new proof-of-presence use cases for guard tours, electronic visit verification or service records
• NFC smart payments for credit cards

What Are RFID Readers?

An RFID reader is a device that communicates with RFID tags to retrieve and process data. It emits radio frequency (RF) signals that power passive RFID tags and enable the exchange of information stored on the tag’s microchip. RFID readers are essential for identifying, tracking and managing tagged assets in industries such as retail, logistics, healthcare and manufacturing.

Types of RFID Readers

RFID readers come in various types designed for specific applications, including:

• Fixed RFID Readers: Installed at entry points, conveyor belts, warehouse shelves or checkout counters, these readers continuously scan and track RFID-tagged items as they move through a facility
• Handheld RFID Readers: Portable and versatile, these readers allow for on-the-go scanning of RFID tags, making them useful for inventory counts, asset tracking and field operations
• Integrated RFID Readers: Embedded within self-checkout kiosks, POS systems or smart cabinets, these readers automate tracking and transactions without human intervention
• Mobile RFID Readers: Connected to smartphones or tablets via Bluetooth or USB, these compact readers bring RFID functionality to mobile applications for scanning and data collection

RFID Reader Frequencies

RFID readers operate at different frequency ranges, depending on the RFID system and application:

Some RFID readers are designed to read multiple RFID frequencies, making them versatile for multi-application environments. These multi-frequency readers allow businesses to use a single reader for various RFID systems, reducing hardware costs and improving operational flexibility.

Key Features of RFID Readers

RFID readers have various features that enhance their performance and functionality, including:

• Read and Write Capability: Unlike barcode scanners, RFID readers can both retrieve and update tag information
• Multiple Tag Reading: Can scan hundreds of tags simultaneously, unlike barcodes that require one-by-one scanning
• Long Read Range: UHF RFID readers can capture tags from several meters or feet away, depending on the system’s power and antenna configuration
• Connectivity Options: Readers can transmit data via Wi-Fi, Bluetooth, Ethernet or USB, allowing for seamless integration with business systems
• Integration with IoT and AI: Advanced RFID readers connect to cloud-based platforms, AI-driven analytics and automation systems, enhancing real-time decision-making

RFID readers serve as the core component of an RFID system, ensuring efficient asset tracking, process automation and enhanced visibility across various industries.

Can an RFID Reader Read Multiple Tags?

Some low frequency (LF) readers are designed to read only one tag at a time, e.g., the ID of a single cow, sheep or other livestock’s ear tag. High Frequency (HF) and especially Ultra-High Frequency (UHF) readers are designed to read multiple RFID tags concurrently, e.g., a stack of tagged books or a pallet of goods moving through a reader gate. Modern UHF readers can read over 1,000 tags per second!

What Is an RFID antenna?

An RFID antenna is a critical component of an RFID system, responsible for transmitting and receiving radio frequency (RF) signals between RFID tags and the RFID reader. The antenna enables the system to communicate with tags by generating an electromagnetic field, which powers passive RFID tags and facilitates data exchange.

RFID antennas come in various sizes, shapes and frequencies, depending on the application. They can be integrated into handheld readers or installed as fixed antennas at key points like entryways, conveyor belts or warehouse docks. The type and configuration of the antenna influence the read range, coverage area and performance of the RFID system.

Key factors that affect RFID antenna performance include:

• Frequency Range: Low Frequency (LF), High Frequency (HF) and Ultra-High Frequency (UHF) antennas each have different capabilities and ranges
• Polarization: Linear antennas provide long-range reads in a single direction, while circularly polarized antennas capture tags at various angles
• Form Factor: RFID antennas vary from small, embedded designs for compact devices to large, panel-style antennas for wide-area coverage

RFID tags also contain their own built-in RFID tag antenna, which is connected to the RFID chip. This tag antenna captures energy from the RFID reader’s signal, powers the chip and transmits data back to the reader, enabling seamless identification and tracking.

What Are the Advantages of RFID Over Other Technology?

RFID is often compared with other identification and tracking technologies, each of which has its own strengths and use cases. Below are key comparisons between RFID and other commonly used technologies:

RFID vs. Barcode:

One of the key advantages of RFID over traditional barcode technology is that it provides a unique ID and does not require a direct line of sight to identify assets or products. This capability makes RFID ideal for use in challenging environments, such as cold storage, hazardous locations or outdoor operations, where traditional barcode systems may fail.

RFID technology offers several advantages over traditional barcode systems. Key differences between RFID and barcode technology include:

• Line of Sight: Barcodes require direct line of sight to be scanned, meaning each item must be individually aligned with the scanner. In contrast, RFID does not need a line of sight, allowing tags to be read in bulk, even if hidden or placed behind objects
• Data Capacity: Barcodes store limited information, usually just a single identifier, while RFID tags can hold more complex data and can be read or written to multiple times
• Durability: RFID tags are more durable than barcodes, which can become unreadable if the label is damaged, faded or torn
• Speed: RFID systems can scan hundreds of tags simultaneously, while barcodes need to be scanned one at a time, making RFID faster for tasks like inventory tracking or asset management
• Item-level Serialization: RFID allows for a unique ID providing the serialization of each product down to the item level for more accurate tracking purposes, whereas 1-D barcodes are all identical for a specific product or SKU number

RFID vs. NFC:

Below are key differences between RFID and NFC:

• Technology: Near Field Communication (NFC) is a subset of high-frequency (HF) RFID, designed for very short-range communication (typically a few centimeters)
• Range: RFID, particularly UHF, can work over longer distances (up to 12 meters or more), while NFC is limited to short-range interactions
• Use Cases: NFC is commonly used in smartphones for contactless payments, pairing devices and transferring small amounts of data. Other forms of RFID, such as RAIN RFID, is used for applications requiring longer range and bulk data collection, such as supply chain management and asset tracking

RFID vs. Bluetooth:

Here’s a comparison of how RFID differs from Bluetooth:

• Power Source: RFID tags are typically passive, meaning they do not require a power source and rely on the reader to power the RFID tag so the tag can transmit its data. Bluetooth devices, however, require a battery or external power
• Range: Bluetooth has a range comparable to UHF RFID (typically 10 to 100 meters) but is primarily used for data transmission between devices, such as in wireless headphones or mobile phones. RFID is optimized for identification and tracking applications, not continuous data transmission.  Bluetooth tracking solutions lend themselves to use cases where long read distances are required, such as outdoor storage yards, large expansive warehouses and buildings with many rooms and assets such as hospitals.  Bluetooth is also used for RTLS (Real-Time Location System) where assets or products need to be tracked in large areas to within a few meters of accuracy
• Cost: RFID tags are generally cheaper than Bluetooth devices, making RFID more suitable for applications involving large numbers of items, like inventory or asset tracking

RFID vs Barcode, NFC and Bluetooth: Key Differences and Use Cases

What Are the Benefits of RFID?

Passive RFID tags offer several advantages over alternative technologies like barcodes and QR codes, making them a powerful tool for inventory management, asset tracking and automation. Key benefits include:

Reduced Human Error: Automates the tracking process, minimizing mistakes associated with manual data entry

No Line of Sight Required: RFID tags can be embedded within products, covered in dirt or placed out of direct view and still function correctly

Unique Serialization: Each tag has a distinct identifier, making it possible to track individual items that would otherwise be indistinguishable

Read/Write Capability: Unlike barcodes, which are read-only, RFID tags can store and update data as needed

Large Memory Capacity: Some RFID chips can store up to 32KB of data, enabling detailed tracking information

Enhanced Security: Optional cryptographic encryption or password protection adds a layer of security

Extended Read Range: RAIN Ultra-high frequency (UHF) and active RFID tags can be read from several meters or feet away

Bulk Scanning: RFID readers can capture data from multiple tags at once, making it possible to scan entire pallets or shipments in seconds

Wireless Sensor Integration: Some RFID tags can monitor environmental conditions, such as temperature, humidity or mechanical strain, for enhanced asset tracking

For more details on selecting the right RFID tag for your needs, check out the white paper: Top 7 Considerations to Choose the Right RFID Tag for more details.

How Has RFID Been Used?

RFID technology has its roots in World War II, where radar was used to identify whether nearby aircraft were friend or foe—a concept that laid the groundwork for modern RFID systems. Since its formal introduction in the 1970s, RFID has evolved and found applications across a wide range of industries:

Where Have RFID Tags Been Used and Who Uses Them?

Industries worldwide leverage RFID technology for diverse applications, including:

• Animal and Agricultural Tracking: Early applications included tagging animals or plants for identification and monitoring, such as livestock management and wildlife research
• Access Control: RFID-enabled ski passes, access cards and other systems simplify entry management and improve user convenience
• Aerospace and Defense: RFID is essential for tracking assets, managing parts inventories and maintaining operational efficiency in high-stakes environments
• Consumables: RFID helps in monitoring the usage and inventory of consumable goods such as food, beverages and pharmaceuticals, reducing waste and improving supply chain management
• Construction: RFID is employed for tracking materials, equipment and tools on construction sites, improving inventory visibility, reducing theft and enhancing project timelines
• Energy, Utilities and Smart Cities: RFID supports urban infrastructure, such as waste management, parking systems and traffic monitoring
• Libraries and Education: Libraries utilize RFID to automate book checkouts, returns and inventory management, while schools use it for student tracking and attendance
• Medical and Healthcare: RFID is widely used for inventory tracking, supply chain management, patient identification, medication tracking and surgical tool monitoring to improve safety and efficiency
• Manufacturing and Automotive: Manufacturers use RFID for production automation, real-time inventory management, efficiency modeling and quality control, enabling smarter and more streamlined processes
• Retail and Textiles: Retailers leverage RFID for inventory accuracy, theft prevention, customer behavior tracking and automating checkout systems
• Transportation and Logistics: RFID tags are critical in toll collection, fleet management, shipment tracking and optimizing delivery routes
• Oil and Gas: RFID is used for tracking and managing tools, equipment and pipelines, as well as monitoring assets in harsh and remote environments to enhance operational safety and efficiency
• Returnable Transport Items (RTIs): Companies use RFID to track reusable containers, pallets, kegs and other RTIs to ensure accountability and optimize their usage
• Ticketing and Event Management: RFID wristbands and badges streamline attendee tracking, access control and cashless payments at concerts, conferences and large-scale events

RFID’s adaptability across industries demonstrates its vast potential for solving diverse operational challenges and enhancing efficiency. Find the best RFID for your application.

RFID Use Cases

RFID tags are primarily used to uniquely identify the items they are attached to or embedded in. Their applications span a wide range of industries and support virtually any physical object. The common benefits of RFID tag usage include:

• Improved inventory speed and accuracy: Automates tracking, reducing time and labor costs
• Elimination of human error: Ensures reliable data capture without manual entry mistakes
• Optimized logistics workflows: Streamlines the movement, handling and tracking of items
• Contactless payment: Enables secure and seamless transactions
• Access control: Enhances security by managing entry to restricted areas or systems

Additional RFID applications include:

• Faster inventory cycles
• Receiving, shipping and all distribution steps in the supply chain
• Product picking and retrieval
• Geofencing for location-based tracking
• Work-in-progress (WIP) tracking in manufacturing
• Environmental monitoring (temperature, humidity, pressure, etc.)
• Machine validation and auto-calibration
• Check-in and check-out operations for equipment, vehicles and assets

RFID technology continues to expand across industries, providing greater efficiency, security and automation in everyday operations.

Is RFID Safe for Humans?

Yes, RFID is safe for humans. The radiation emitted by RFID systems is very low and only active for brief periods when the system is in use. In fact, the signals from an RFID system have a significantly lower radiation level than those emitted by traditional cell phones. Furthermore, the FDA has not identified any adverse health effects associated with RFID technology, making it a safe and widely used tool in various industries.

What Are the Cost Considerations for RFID?

The cost of RFID tags can vary widely based on their type, durability and functionality. The most affordable RFID tags—often just a few cents per unit—are simple, thin, adhesive labels commonly used in retail and logistics for one-time use in non-rugged environments. These cost-effective passive RFID tags provide basic tracking capabilities but may not withstand harsh conditions.

As performance requirements increase, so does the cost. Factors such as chip capability, memory size and durability influence pricing. RFID tags designed to endure extreme temperatures, moisture, chemicals, impact or prolonged sun exposure can cost a few dollars each due to their specialized materials and construction. Rugged hard tags, which offer better protection and longevity, typically cost more than standard passive labels.

Active RFID tags, which include an internal battery for extended read range and real-time tracking, are significantly more expensive than passive tags. These tags also require maintenance or battery replacement over time, adding to their overall cost. Additionally, active tags are generally larger due to the need for battery housing and additional components.

Understanding RFID Tag Pricing

Several factors influence RFID tag pricing, including:

• Performance requirements (e.g., required read range)
• Mounting location and available space on the asset
• Type and brand of microchip (memory size, read/write capabilities)
• Environmental conditions (temperature, UV exposure, chemicals, impact, sterilization needs)
• Expected tag lifespan
• Purchase volume (bulk pricing can significantly reduce costs)

Ultimately, while RFID tags represent an upfront investment, the value they bring through enhanced asset tracking, efficiency and security makes them a cost-effective solution for many industries.

RFID tags for end users are typically sold through system integrators of HID Global. To find a sales partner in your region, use the HID Partner Locator. If you are an HID Partner, you can purchase RFID tags directly from the HID Global Web Shop.

What Are Future Trends in RFID?

RFID technology continues to evolve, driving greater efficiency, automation and intelligence across industries. As RFID systems become more advanced, several key trends are shaping the future of the technology:

• Smaller Form Factors & Extended Capacity: RFID tags are becoming more compact and lightweight, enabling seamless integration into smaller products, medical devices and high-density packaging. At the same time, advancements in RFID chip design are increasing memory capacity, read range and processing capabilities
• Integration with Robotics & Automation: RFID is playing a crucial role in automated warehouses, manufacturing and logistics by providing real-time tracking and process optimization. Robotics equipped with RFID readers can autonomously identify, sort and transport goods, improving efficiency and reducing human intervention
• Miniaturization & Embedded RFID: The continued miniaturization of RFID chips allows for discreet, embedded tagging in products ranging from luxury goods to industrial components. This trend enhances anti-counterfeiting, supply chain visibility and asset authentication
• AI-Driven RFID Analytics: Artificial intelligence (AI) is being leveraged to analyze vast amounts of RFID data, enabling predictive insights, anomaly detection and smarter inventory management. AI-powered RFID systems can identify patterns, reduce waste and enhance decision-making in industries such as retail, healthcare and logistics
• RFID in Digital Modeling & Twin Technology: RFID is increasingly used in digital twin modeling, where physical assets are mirrored in a virtual environment. This technology allows businesses to simulate operations, track performance and optimize workflows using real-time RFID data
• Expanded Sensor Capabilities: Modern RFID tags are integrating sensors for temperature, humidity, pressure and strain, allowing industries like pharmaceuticals, agriculture and food safety to monitor environmental conditions remotely
• 5G and IoT Connectivity: As 5G networks and IoT (Internet of Things) adoption expand, RFID platforms will benefit from faster data transmission, lower latency and enhanced cloud connectivity, making RFID-driven automation even more powerful

As these innovations continue to develop, RFID technology will become even more intelligent, adaptable and essential in a wide range of applications, from smart cities and supply chain optimization to healthcare and AI-driven automation.